Get access to everything we publish when you sign up for Outside+.
While you may prefer to keep your feet on dry land, you won’t get a better return on your investment than from swimming—especially if you’re a new runner or you’re prone to injuries. Swimming introduces new ranges of motion and strengthens muscle groups that have been neglected, helping a runner avoid classic overcompensation injuries. It can also help develop lung capacity improve ankle flexibility, strengthen your core muscles, and allow you to boost your weekly training volume without risking injury.
In fact, hopping in the pool may do more to help you bounce back from a tough run than compression socks, ice baths, or Normatec boots, according to a study published in the International Journal of Sports Medicine.
Researchers at the University of Western Australia had nine well-trained triathletes perform an interval run consisting of 8 x 3 minutes at 85–90 percent VO2 peak velocity on two separate occasions. Ten hours after the run, the triathletes either swam 2,000 meters or lay down for an equal amount of time. Fourteen hours after that, the subjects performed a high-intensity run to fatigue to assess how well their running performance had recovered from the previous day’s interval sessions. Interestingly, the subjects were able to run for 13 minutes, 50 seconds after swimming for recovery compared to only 12 minutes, 8 seconds after lying still for recovery. That’s a 14 percent difference.
The researchers also found that swimming for recovery was associated with much lower levels of c-reactive protein, a biomarker of inflammation, 24 hours after the interval run. This finding suggested that swimming for recovery enhanced performance in a subsequent run by attenuating muscle tissue inflammation resulting from the first run.
It’s easier than you think to get started. Simply swap a swim session for one or two runs (think an afternoon recovery run or a 4-mile morning jog) each week, using our quick tips.
WHAT YOU’LL DO: Choose (and alternate) between water running or lap swimming. There are two types of water running—shallow water running (where you’re in waist-deep water, running across the bottom of the pool) and deep water running (where you’re in deep enough water that your feet don’t touch the bottom of the pool). Both forms of water running work the body in a similar manner and require the same mechanics.
When water running, the body should remain as vertical in the water as possible, avoiding leaning forward at the chest, with the arms and legs pumping like pistons—similar to the motion of running on land. Deep water running can be completed with or without a flotation belt (though beginners should start with a belt—it’s far more difficult to maintain proper form without it).
The great part about pool running is that you can do nearly identical workouts to those you’d do on the road or track. For instance, if you had an 8×400-meter workout planned and you usually run 400 meters in about 90 seconds, simply surge in the pool for the same amount of time.
In the same manner, if you simply need a short easy day, jog in the pool at a relaxed pace for 30 minutes. You can apply these same principles to lap swimming, as well. If you’re looking for aerobic exercise, you may simply swim steady laps for a certain amount of time. For a more anaerobic workout, however, you can do pool sprints. Not unlike intervals done on the track, this requires you to surge for a certain distance. For instance, you could do 10×50-meter sprints with 30 seconds recovery in between, increasing the number of intervals as you get stronger.